The invention concerns a microtome comprising a base frame on which is provided a specimen holding device for performing a vertical cutting movement, and a knife holding device for a cutting element which is formed by a cutting knife or a cutting blade combined with a blade holder.
Such a microtome can be a table microtome or a cryostat microtome.
DE 42 05 257 C2 describes a rotational microtome comprising a base plate on which a base frame with a microtome housing is arranged at the rear and on which a knife holding device is arranged at the front. To receive thin sections of a thin section specimen which is clamped in the specimen holding device of the rotational microtome, that known rotational microtome has a trough configuration comprising two mutually spaced side portions and a front portion connecting the side portions together. The trough configuration therefore has a U-shaped area in plan, which matchingly encloses the knife holding device on three sides. The two side portions of the trough of U-shaped configuration terminate at least approximately flush with the rearward microtome housing at the outside thereof.
A microtome with a control desk which includes operating elements for setting various parameters such as section thickness feed speed, trimming section thickness, section thickness and optionally a display device for displaying the set parameters is known from DE 42 05 258 C2. That known microtome has a receiving portion which is adapted for releasably fixing the control desk. That known microtome also provides that the base frame with the microtome housing is arranged at the rearward end portion of a base plate and the knife holding device is arranged at the front end portion of the base plate.
Known microtomes, in particular rotational microtomes, usually have a base plate, at the rearward end portion of which the base frame is arranged and at the forward end portion of which is arranged the knife holding device. Such a base plate and mounting of the base frame and the knife holding device on the base plate involve an assembly complication and expenditure which has an effect on the manufacturing costs of such a known microtome. The base plate and mounting of the base frame and the knife holding device on the base plate can also have an adverse influence on torsional stiffness and stability of the microtome when the cutting forces become operative.
DE 38 30 725 A1 discloses a microtome having a drive device which has a shaft with a hand wheel arranged thereon, the hand wheel having a handle. An electromagnet is arranged on the housing frame of the microtome, for arresting the drive device. The electromagnet is in operative relationship with a switching ring displaceable axially on the shaft. A control device connected to the electromagnet and to a sensor controls the electromagnet in dependence on a signal from the sensor. That known microtome has a base frame with a specimen holding device. A base plate projects forwardly from the base frame, at the underside. Projecting vertically upwardly from the front edge of the base plate are two lateral columns, between which a cutting knife is arranged.
DE 88 09 096 U1 discloses a microtome having a housing on which are arranged operating knobs connected to a transmission arrangement for manually setting the parameters which can be selected at the microtome such as section thickness, knife angle and so forth. That known microtome has coaxial operating knobs at both sides, which can be alternately recessed in the microtome housing.
The German journal ‘Zeitschrift für wissenschaftliche Mikroskopie und mikroskopische Technik’, 63 (1958), pages 484 through 494, discloses conventional microtome structures comprising a base plate, on which a base frame with a specimen holding device is mounted at the rear and on which a knife holding device is mounted at the front. The base plate is for example of an inverted U-shaped cross-sectional profile, on which a pattern carrier slide with a knife holder is in turn disposed so that the working and manipulation plane for the operator of the microtome is relatively high. That is disadvantageous from ergonomic points of view. A corresponding consideration also applies in regard to the microtome which is known from the prospectus from Leitz, Wetzlar: ‘Serienschnittmikrotom’, 1510 (1974), page 2, and which also has a box-shaped base element which projects away from the rear base frame with the specimen holding device, at the underside thereof, and on which the blade holding device which is in the form of a blade block is displaceably mounted. The base element involves a relatively great heightwise dimension, and that has a disadvantageous effect on ergonomy and operating comfort.
The object of the present invention is to provide a microtome of the kind set forth in the opening part of this specification, with which it is possible to achieve considerable cost savings, which involves a substantially enhanced level of torsional stiffness and stability when the cutting forces become operative.